October 04, 2023

Will PoE switches consume more power?

The power consumption of PoE switches has always been a concern for buyers of PoE switches. This refers to energy used by PoE switch per unit of time. Some may wonder if value of a PoE switch outweighs electricity bill. This article explains everything you need to know about power consumption of a PoE switch and how to reduce it.

What factors affect power consumption of PoE switches? Power standard

The PoE standard is an important factor influencing power consumption. Since PoE, PoE+, PoE++ are different PoE standards, they provide different power for PD. It is recommended to make sure your PoE switch can support power required by your PD. The table below shows characteristics of various PoE standards.


IEEE Standard

Power supply for powered devices (PD)

Max. Power per port

Supported devices


IEEE 802.3af



Fixed surveillance cameras, VoIP phones, wireless access points


IEEE 802.3at



PTZ cameras, IP phones, alarm systems


IEEE 802.3bt (type 3)

51 W


Video conferencing equipment, wireless access point with multiple radios


IEEE 802.3bt (type 4)



Notebook, tablet

Number of PD (Powered Device) connections

The number of PDs connected to a PoE switch is another factor that affects power consumption of a PoE switch. The more PDs connected to a PoE Ethernet switch, more power consumed. For example, if 10 PoE IP cameras with a power consumption of 7W are connected to a 24-port PoE switch with a power budget of 200W, then 10 PoE IP cameras will generate a total of about 70W of power consumption; similarly, 20 PoE network cameras will generate about 140W of power consumption. In addition, in a large data center, PDs generate heat during operation and may require other equipment such as fans and air conditioners to cool them, resulting in some power consumption.

PoE switch power budget

Power budget is another factor that affects power consumption of PoE switches. Some managed PoE network switches used in large enterprise environments may have a power budget of up to 400W, but for home networks it is advisable to use a basic unmanaged PoE switch with a power budget of only 60W.

port number

The power consumption of PoE switch is also related to port number to meet different power requirements. For example, a small 8-port PoE switch can offer 130W or 250W power as an option, while a 48-port high port density PoE switch can offer up to600W or more.

How to reduce power consumption of a PoE switch? Energy Efficient Ethernet (EEE)

Energy Efficient Ethernet is short for EEE, a technology defined by IEEE 802.3az to reduce switch power consumption during periods of low network traffic to reduce power consumption by more than 50% while maintaining compatibility with existing equipment. fully compatible. It is also sometimes referred to as Green Ethernet.

In addition to conserving power over link load with Energy Efficient Ethernet, Green Ethernet works in one of two ways. First, it detects state of link, allowing each port on switch to go into idle state when connected device is idle. Second, it determines length of cable and adjusts power used for transmission accordingly. Please note that when choosing a PoE switch, you need to make sure that device ports and connected devices must support 802.3az EEE standard.

Will PoE switches consume more power?
Using Smart PoE

Using Smart PoE is another effective way to reduce your switch's power consumption, which can improve your business ROI. Smart PoE can automatically detect power consumption status of each power device and provide necessary power to PD. And if connected device is not a PoE device, smart PoE switch will not transmit power, which can protect non-PoE device. By using intelligent PoE technology to minimize wasted energy losses, businesses can save significantly on their energy bills.

Will a PoE switch consume more power?

While PoE switches are ostensibly a little more expensive, which increases hardware and power costs, performance gains of PoE switches usually outweigh extra power costs. Because PoE network switches simplify installation and maintenance costs. Users do not need to purchase and install additional wires and sockets.

In addition, good PoE switches support SNMP (Simple Network Management Protocol), which makes it easy to monitor and manage switch.

Therefore, it is short-sighted to focus only on additional power costs when choosing a suitable PoE switch. With benefits of better application integration, increased performance, and IT resource freeing up, your smart choice of PoE switches can help mitigate impact of higher energy bills.

Original link: Will PoE switches consume more power? Weak current smart grid